package LeetCode._03_链表;

import org.w3c.dom.ls.LSException;

public class _10合并两个有序链表 {
    public class ListNode {
       int val;
       ListNode next;
       ListNode() {}
       ListNode(int val) { this.val = val; }
       ListNode(int val, ListNode next) { this.val = val; this.next = next; }
    }

    public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
        if(list1 == null && list2 == null) return null;
        if(list1 == null) return list2;
        if(list2 == null) return list1;
        ListNode newHead = new ListNode(0);
        ListNode tmp = newHead;

        while(list1!=null && list2!=null){
            if(list1.val<= list2.val){
                tmp.next = list1;
                list1 = list1.next;
            }else{
                tmp.next = list2;
                list2 = list2.next;
            }
            tmp = tmp.next;
        }

        if(list1!=null){
            tmp.next = list1;
        }else{
            tmp.next = list2;
        }
        return newHead.next;
    }

}
